Laser solid forming additive manufacturing TiB2 reinforced 2024Al composite: Microstructure and mechanical properties

The 2024Al alloy and 3%TiB2 reinforced 2024Al composite were fabricated using laser solid forming (LSF). Different from the LSF processed 2024Al with a large columnar grain and apparent preferential growth orientation, TiB2 reinforced 2024Al composite presents texture-less structure, consisting of the dendrite and fine equiaxed structures. Some TiB2 particles distribute within the Al matrix, others distribute along the grain boundaries and intertwine with the Al2Cu phase. The incorporation of TiB(2 )gives rise to significant grain refinement, which is one of the important reasons for the improvement of mechanical properties. Moreover, the TiB2 reinforced 2024Al sample exhibits 284 MPa high tensile strength, 163 MPa yield strength, 108.5HV microhardness, and 18.7% excellent elongation.